class Solution:
    def longestCommonPrefix(self, strs: List[str]) -> str:
        if len(strs) == 1:
            return len(strs[0])
        first_str = strs[0]
        cnt = ""
        pos = 0
        for idx, st in enumerate(strs[1::]):
            if first_str[pos] == st[pos]:
                pass
